Also there are some advertisements not for rings but use the meaning of ring as a reminiscent.
For example this award-winning Turkish advertisement for pasta says 'A happy relationship...' and one piece of pasta symbolises the ring on the fork.
KTB Network uses the understanding of 'diamond enhances the value of a ring.'
This correlation represents the relationship between the customer and the network. It also uses the word "partners" to highlight the intention.
References:
http://www.118haber.com/haber/mutlu-makarnaya-odul-418683.htm
http://www.coloribus.com/adsarchive/prints/venture-capital-ring-3680555/